Method of making decorative panels

ABSTRACT

A sheet of building material having a decorative outer surface comprising an embossed panel with segments of different thickness and grooves formed in the outer surface between adjacent segments, said outer surface covered with a first ground coat of solid color, a second coat of stain applied and wiped to provide elongated streaks, a third solid color ground coat applied to the surface of said segments exclusive of said grooves and a finish coating comprising a printed pattern of wood grain. Apparatus for the production of said decorative panels includes means for applying a liquid coloring agent over said surface and wiping the same with an elongated belt of woven fabric movable relatively over the surface at a selected rate and biased into wiping contact with said surface by a rotary brush having a plurality of bristles, with free ends of bristles relatively movable with respect to the woven fabric belt and rotated to movingly penetrate at least some of the openings in said woven fabric thereby forming elongated streaks of coloring agent on said surface of said panel.

United States Patent [1 1 Daunheimer et al.

[ Nov. 12, 1974 METHOD OF MAKING DECORATIVE PANELS [75] Inventors: LynR. Daunheimer, Batavia;

William M. Irvine, Lombard, both of 111.

[73] Assignee: Masonite Corporation, Chicago, Ill.

[22] Filed: Sept. 11, 1972 [21] Appl. No.: 287,682

[52] US. Cl. 117/37 R, 117/64 R, 117/65.2, 117/102 R, 117/102 L, 117/111C [51] Int. Cl B44d 5/10 [58] Field of Search 117/37 R, 43, 64 R, 65.2,117/102 R, 102 L, 111 C, 39, 45; 52/113;

[56] 1 References Cited UNITED STATES PATENTS 7 3,271,184 9/1966Poletika et al ll7/65.2 3,600,346 8/1971 Spatola 260/22 R PrimaryExaminerThomas J. Herbert, Jr. Assistant ExaminerBruce H. Hess Attorney,Agent, or Firm-Mason, Kolehmainen, Rathburn & Wyss A 22 22 22@ I 1 A '6Q a [57] ABSTRACT A sheet of building material having a decorative outersurface comprising an embossed panel with segments of differentthickness and grooves formed in the outer surface between adjacentsegments, said outer surface covered with a first ground coat of solidcolor, a second coat of stain applied and wiped to provide elongatedstreaks, a third solid color ground coat applied to the surface of saidsegments exclusive of said grooves and a finish coating comprising aprinted pattern of wood grain. Apparatus for the production of 7 Claims,6 Drawing Figures a km 9ATENTEDHUV 12 I974 SHEET 2 OF 2 FIG. 2

i 4. or

METHOD OF MAKING DECORATIVE PANELS The present invention relates to anew and improved decorative building panel and more particularly to abuilding panel having a decorative outer surface resembling that ofV-groove wood planks laid side to side. The panel is formed with aplurality of segments of different thickness, and grooves are formed inthe simulated joints between adjacent segments to make the panel have anappearance of actual V-groove type wood planks laid side by side.

In prior art paneling sheets decorated to resemble V- groove wood plankslaid side by side, difficulty has been encountered in providing suitablefinishing techniques for the surfaces of the V-groove joints betweenadjacent plank sections. The deep relief of such joints greatly improvesthe appearance of the paneling, however, requiring a higher cost becauseof the difficulty of treating and properly finishing the surfaces of thegrooves.

In wood grain decoration on panel sheets, the wood grain pattern isusually applied with a roll in a liquid form such as ink or othercoloring agent, and the printing pattern is usually developed from aphotograph taken of actual V-groove type wood planks laid side by side.Another difficulty has been encountered in obtaining uniform applicationof a wood grain printed pattern on the outer surface of a panel whensegments of the surface are at different levels due to differentthicknesses of portions of the panel sheet. Another problem has been theextremely difficult task of obtaining an authentic appearing stainedpanel having randomly oriented lines or streaks resembling thoseproduced by the old time hand craftsman when using antique finishingtechniques.

It is an object of the present invention to provide a new and improveddecorative panel sheet.

Another object of the present invention is to provide a new and improveddecorative panel sheet of the type having a decorative outer surfaceresembling that of actual wood planks laid side by side.

Another object of the invention is to provide a new and improveddecorative panel of the character described having sections resemblingwood planks of different thickness with grooves formed between adjacentsections.

Another object of the present invention is to provide a new and improvedpanel sheet of the character described wherein the surfaces of thegrooves are provided with embossed wood grain patterns therein.

Still another object of the present invention is to provide a new andimproved method of finishing the decorative outer surface of panelsheets of the character described.

Another objectof the present invention is to provide a new and improvedfinishing method wherein a coloring agent such as stain is applied overthe surface of a decorative panel and is thereafter wiped to producerandom orientated streaks.

Still another object of the present invention is directed toward theprovision of novel apparatus for the mass production finishing ofdecorative panel sheets including novel means for applying liquidcoloring agents and subsequently wiping the same to provide a streakedeffect having the appearance of a wiping stain.

Another object of the present invention is to provide a new and improvedapparatus for producing paneling of the type described wherein thesurfaces of the grooves formed in the panel are treated with stain andthereafter the stain is wiped slowly with a woven fabric biased intocontact by rotary brush means to provide random orientated streaks.

The foregoing and other objects and advantages of the present inventionare accomplished in a new and improved paneling sheet of buildingmaterial having a decorative outer surface comprising segments ofdifferent thickness with grooves formed between adjacent segments. Thesurface of the panel sheet is covered with a first ground coat of solidcolor, a second coat of stain is applied and wiped with woven fabric toprovide elongated streaks, a third solid ground color coat is appliedonly to the surface of the segments exclusive of the grooves, and afinal or finish coat comprising a V printed pattern of wood grain isthen applied onto the segments.

A novel apparatus in accordance with the present invention providesmeans for applying a liquid coloring agent such as wiping stain over thesurface of the panels passing through the same and for slowly wiping thestain with an elongated belt of woven fabric which is relatively movableover the surface at a controlled rate and which is biased into wipingcontact against the surface of the panels by a rotary brush having aplurality of bristles. The outer free ends ,of the bristles are adaptedto rotate and movingly penetrate through at least some of the openingsin the woven fabric and engage the stain thereby forming elongatedstreaks resembling a hand wiped stain.

For a better understanding of the present invention reference should behad to the following detailed description taken in conjunction with thedrawings in which:

FIG. 1 is a side elevational, schematic view of the 'new and improvedmachine for decorating the outer surface of a building panel inaccordance with the features of the present invention;

FIG. 2 is a fragmentary sectional view taken substantially through lines22 of FIG. 1;

FIG. 3 is a photograph of a sheet of paneling in accordance with thepresent invention taken after only the first solid color ground coat hadbeen applied to the surface thereof;

FIG. 4 is a photograph of the paneling sheet taken after the applicationof a second coating of stain has been applied and wiped;

FIG. 5 is a photograph of the paneling sheet taken after a third solidcolor ground coat has been applied on the surfaces of the plank segmentsexclusive of the grooves between adjacent segments; and

FIG. 6 is a photograph of a finished panel sheet in accordance with thepresent invention taken after the final application of a wood grain,printed pattern.

Referring now more particularly to the drawings, a new and improveddecorative, embossed building paneling sheet constructed in accordancewith the present invention is shown in FIG. 6 and is generally referredto by the reference numeral 10. The finished sheet of paneling 10 isdecorated to appear similar to actual V- groove, tongue and groove typewood planks joined side by side and includes a plurality of segments orsections 12 resembling individual wood boards or planks, some of whichare thicker than others as best indicated and 12b (thinner sections).

"Between each pair of adjacentsections 12 each of which resembles asurface of an individual plank or board of lumber, there is formed anindented, elongated groove 14 having a pair of inwardly sloped,angularly intersecting, opposite surfaces 16 to provide the same visualeffect as a V-groove joint between adjacent boards or planks. As bestshown in FIGS. 4 and 5, the surfaces 16 of the grooves 14 are embossedwith grain patterns therein and accordingly are relatively difficult tofinish on automatic equipment because of variations in the surface. Itis desirable that the groove surfaces be finished to appear the same asactual wood after finishing is complete. It should be noted that manyprior art panels have dark. coloring of a solid naturein thegrooves,'which coloring detracts from the authenticity of the appearanceof the finished panels and which does not accurately portray V-groovejoints between planks.

The paneling sheets are preferably formed with ,a hydraulic press, atrelative high temperature and pressure, and the materials used normallycomprises wood fibers or chips which have been exploded into small sizefibrous pieces. .T he pieces are mixed and heated with steam and finallyare compressed under extremely high pressure and temperature with anembossed pressure plate to provide the sectionthickness variations andthe authentic appearing V-groove joints with embo'ssedgrain patternstherein. The assignee of this application makes and sells panelingsheets of the same general type under the trademark MASONITE, howeverpaneling sheets of other construction and materials such as fiber board,particle board, pressed wood etc. may be utilized when decorated inaccordance with the present invention to closely resembly V-g'roove woodplanks or boards laid side by side.

In accordance with the present invention, blank paneling sheets 10formed of pressed wood fiber material and the like with an outer surfaceembossed with V- grooves therein as described, are first passed througha ground coating paint or color applicator station, preferably of theroll type such as shown and described in the US. Pat. applications Ser.No. 244,623 filed Apr. 17, 1972 and Ser. No. 178,556 filed Sept. 8,1971, which applications are assigned to the same assignee as thepresent application and which applications are incorporated herein byreference. After the paneling sheets 10 have been covered with the firstsolid color ground coat, the decorative surface of the paneling sheetsappear as shown in the photograph of FIG. 3. The ground coat applicationprovides a solid color base for the subsequent application of staincoloring agents, such as paint or ink in printed patterns. The color ofthe first coat is chosen to provide a base or background compatible withthe type of wood which is to be resembled by the finished panelingsheets. It should be noted that the grooves 14 and the surfaces 16thereof are formed with embossed grain patterns therein, however, thegrain pattern does not stand out in deep contrast as shown in FIG. 3after the application of the first ground coat. A single application ofa solid color ground coat alone does not particularly enhance the reliefappearance of the grooves formed in the panels, and subsequent finishingsteps in accordance with the invention produce a dramatic and pleasingchange in appearance.

After the panels 10 have received the first solid color ground coatapplication which has been dried, they appear as shown in the photographof FIG. 3. These panels are next passed through a stain applicator asindicated schematically in FIG. 1 and referred to generally by thereference numeral 20. The novel stain applicator 20 in accordance withthe invention includes a plurality of support rolls 22 for carrying theground coated panels 10 along a horizontal path as indicated. Inaddition to the individual support rolls 22 there is provided a firstpair of pulling pinch rolls 24 and 26 which are adapted to move thepanels l0'into and through the stain applicator 20. The lower roll 24 ofthe first pair of pinch rolls is power driven by means of an endlesschain 28 which chain drivingly interconnects the roll 24 with the lowerone of a second pair of pulling rolls 30 and 32 at the outlet or exitend of the stain applicator. The endless chain 28 is drivingly engagedwith a plurality of separate, lower-support rolls 34, 36 and 38 whichare spaced intermediate the pairs of pinch rolls at the entry and exitend of the apparatus. As indicated schematically in FIG. 1 a number ofidler sprockets 40 are provided to maintain the proper tension on thechain drive, and each. of the drive rolls 24, 30, 34, 36- and 38 issupported. on a horizontal axle for free rotation as driven by the chainthrough a sprocket 42 on the roll shaft. The lower exit roll 30 isrotated at a controlled and adjustable speed by means of a drive chain44 which interconnects a driven sprocket 46 on the roll shaft with asprocket 48 on the output shaft of anelectric motor powered, variablespeed, main drive, gear reducer unit 50. t

In an apparatusconstructed in accordance with the present invention, thereduction gear unit 50 and/or electric drive motor was selected in orderto provide a wide variable speed range of feed for the panels 10 movingthrough the apparatus 20. The drive unit was selected to provide a speedvariation from a minimum of approximately 45' feet per minute to amaximum of over feet per minute. The driven upper pinch rolls 26 and 32are spaced above the respective lower, driven pinch rolls 24 and 30, andthe upper rolls are adjustable in a vertical direction as shown by thearrows A so that the desired contact pressure may be maintained upon thepaneling sheets 10 to pull them through at the desired speed. In thisconnection it should be noted that the contact pressure is increasedsomewhat at higher feeding speeds and may be reduced somewhat at lowerfeeding speeds because of the decreased tendency to slip.

In accordance with the present invention, a fast drying liquid stain ofthe proper color or tint is applied onto the upper decorative surface ofthe paneling sheets 10 as they move through the stain applicator 20. Thestain is supplied from a liquid trough 52 extending across the sheetsand having an elongated dam or weir 52a over which is flowed a thincurtain of stain. The liquid curtain of stain moves downwardly onto thepanels guided by a sloped applicator strip 54. The stain is flooded overthe entire upper surface of the moving panels 10 at a controlled flowrate and is spread and disbursed over the sections 12 and into thegrooves 14 by means of a first squeegee type applicator 56 having ablade 58 formed of rubber or other flexible material capable ofdeflecting enough to move the stain down into the groove surfaces 16 andthe grain patterns formed therein.

After the panels pass the first spreader blade 58, most of the stainedsurface is covered uniformly and the stain is evenly distributed. As thepanels continue to move, they pass under a first rotary brush-assembly60 which includes a drum 62 having a plurality of radial bristles formedof polypropylene plastic material and having crimped or bent over outerends for engagement with the panels. As indicated in FIG. 1, the drumand bristles are rotated in a counterclockwise direction so I that therelative bristle movement is counter to the direction of movement of thepaneling sheets at the region of contact between the bristles and panel.The rotary drum is adjustably movable in a vertical direction (arrows B)to increase or decrease the amount of bristle contact with the stainedsurface of the panels. The drum 62 is driven to rotate at adjustablespeeds varying in a range of 200 to 600 rpm. An electric motor 63 ofvariable speed and a gear reduced 64 are connected to drive the drum ofthe brush assembly through a belt drive 65.

The flexible squeegee-like blade 58 serves to distribute the stain overthe entire surface of the paneling sheets and removes much of the excessstain that is present. The rotating bristles on the drum 62 similarlyserve to evenly distribute the stain over the entire surface of thepaneling sheets while working the stain in thoroughly intothe grainpattern indentations in the groove surfaces 16. Any excess stainremaining is also removed by the rotating bristles which act to help drythe stain by creating an air flow over the surface. As the rotatingbristles pass over the panels in a direction contra to that of panelmovement, the excess stain is sort of swept off and the stain issubstantially uniformly distributed over the entire upper surface of themoving panel sheets and is thoroughly worked into the indentations inthe embossed grain pattern.

As the panels continue to move through the stain applicating apparatus20, they pass beneath a second squeegee-like mechanism 66 having a blade68 like that of the blade 58 formed of flexible material such as rubber.This blade removes any excess stain that may remain on the upper surfaceof the panels after passage through the first brush roll assembly 60.The panels move past the second squeegee-like blade 68 and passunderneath a plurality of holddown disks 70 which are spaced apart on atransverse axle 72. The disks maintain the paneling sheets 10 in drivingengagement against the drive rolls 34 and 36. The panels then pass undera second rotary brush assembly 73 similar to the first rotary brushassembly 60, and the brush action is similar and will not be describedin detail herein. The second rotary brush assembly rotates in acounterclockwise direction and its speed is adjustable so that the drum74 rotates in a speed range from 200 to 600 rpm with the tips of thebristles operating in a speed range of 267 feet per minute toapproximately 1,100 feet per minute relative to the surface of thepanels. The second rotary bruxh assembly is driven by a variable speedelectric brush 75 and gear reducer 76 connected to the drum 74 by a beltdrive 78.

After passage through the second rotary brush assembly 73, the stain isreduced to a thin, evenly distributed coating over the entire surface ofthe panel sheets 10 and is beginning to become dry and somewhat tacky.With the stain in the described condition, the panels move under asecond set of holddown disks 80 spaced apart on a transverse axle 82 andmove to a stain wiping station indicated generally by the referencenumeral 84.

At the wiping station 84, the somewhat tacky, partially dry staincoating is wiped by an elongated belt 86 of woven stranded material toproduce elongated, random streaks in the stain coat to provide anappearance like that shown in the photograph of FIG. 4. The staincoating is wiped to provide a random orientated streaked effect as mightbe provided in the olden days by an individual craftsman, and thisstreaked stain effeet is especially noticeable on the surface 16 of thegrooves 14 between adjacent plank segments 12. The wiped stain streakson the surface of the segments 12 also provide some slight surfacevariation away from a completely planar surface, and when an additionalsolid color ground coating is applied following the stain wipingprocess, these surface variations in depth provide added authenticityfor the final wood grain printed pattern.

The novel stain wiping station includes an idler supply or feed roll 88for the wiping belt and a driven takeup roll 90. The belt is passedbeneath a pair of idler rolls 92 and 94 adjacent the upper surface ofthe moving panels and spaced on opposite sides of a rotary brush roll 96having a large number of radial bristles formed of polypropylene plasticmaterial 3 to 3 inches long and crimped or bent over at their outer freeends. The bristles are relatively stout and are approximately .014 inchin diameter. In general, the bristles on the drums 62 and 74 are similarand the drum 96 is movable vertically like the others (arrows B) toincrease or decrease the area of bristle contact with the back side ofthe wiping belt 86.

The belt 86 passes over a tensioning idler roll 98 before it is wound upon the take-up roll in a clockwise direction as shown. The wipingmechanism is powered by an adjustable speed electric motor 100 and gearreducer 102 via a belt drive 104 running to a pulley 106 on the shaft108 supporting the brush roll 96. A belt tensioning idler 110 isprovided to accommodate belt adjustments when the brush roll 96 isadjusted. A relatively constant speed ratio is maintained between thewiping belt 86 and the brush roll 96 by means of an interconnectingdrive chain or belt 112 running from a pulley or gear 106 on the brushdrum axle to a pulley or gear 114 carried on a shaft 116 mounted beneaththe takeup roll 90. A knurled drive drum 118 on the shaft 116 drives thetake-up roll 90 of the belt 86 in a clockwise direction as shown, toprovide constant belt speed for the wiping belt. An idler 122 isprovided to tighten or loosen the belt or chain 112 as needed.

In accordance with the present invention, the wiping of the stain by thebelt 86 occurs at a relatively low speed so that only about 6 inches ofbelt travel occurs during the interval of time required for a panel 10which is 8 feet in length, to travel across the wiping station. It hasbeen found that a wiping speed of approximately this value works welland provides a desirable appearance. However, the motor 100 and gearreducer 102 permit a relatively wide range of belt speeds to be utilizedso that speeds can be varied over a range of 6 to 1. It has also beenfound that the type of woven fabric used for the belt is an importantfactor in the finished appearance of the wiped stain, and differentfabrics may require adjustments in wiping speeds. For example, heavycotton duck No. S/55252 purchased from B. J. Seaman & Co. of Chicagowith minimal sizing or unsized works well. I-Iopsacking of a relativelyrough weave with heavy fiber or strand size and relative large openingshas worked effectively.

In accordance with the invention, the rotating bristles of the drum 96urge and bias the woven wiping belt 86 into contact with the panelingsheets 10. The tip speed of the bristles is considerably slower thanthat of the bristles on the first and second brush assemblies 60 and 73.The tip speed of the bristles on the drum 96 is set up to besubstantially the same as the speed of the slow moving belt 86 and themoving mass of bristles form a sort of resilient cushioning effect onthe back side of the belt which urges the belt into wiping contactagainst the paneling sheets 10 moving therebeneath. This cushioningeffect provides for a sort of randomness that the wiped streaks in thestain appear to have, and this is one of the effects that makes thewiped stain appear as an authentic hand wiped job. In addition some ofthe bristles which are moving at a tip speed ranging from 2.6 feet perminute to 15.5 feet per minute may randomly penetrate random openings inthe weave of the belt 86 and come into contact with the stain to providea streaked effect therein. The belt 86 moves at about the same speed asthe tips of the bristles of the rotary drum 96 which act as a biasingforce on the belt to produce the wiped stain effect as if it was done byhand. FIG. 2 illustrates the belt 86 biased in wiping contact with thepanel sheet 10 by the bristles of the brush drum 96, and the drum ismovable vertically as indicated by the arrows B to increase or decreasethe wiping contact area.

After the paneling sheets 10 have passed through the apparatus 20 of theinvention and appear as shown in FIG. 4, they are passed through anothersolid color ground coat applicator wherein only the board or planksegments 12 are covered to provide a base for the final grain patternprinting application in ink. The grooves 14 and surface 16 thereofremain the same before and after the solid color ground coat applicationfollowing the stain and wiping process. However, it should be noticedthat the contrast between the solid color coated plank segments 12 andthe grooves 14 is much greater than before as shown by the difference inappearance between the paneling in FIG. and the partially finishedsheets of FIGS. 3 and 4.

The paneling sheets are then passed through a printing station wherein awood grain pattern (FIG. 6) is applied onto the plank segments 12 andthen a clear seal coat is applied over the entire decorative surface ofthe paneling sheets to produce the finished panels is illustrated, whichpanels closely resemble the actual thing.

The building panels may comprise wood particles and/or wood fibersformed under pressure and may also comprise plywood sheets or embossedplywood sheets wherein the decorative outer face is formed with sectionsof different thicknesses and grooves along the joints between thesections. Mineral filler or gypsum board panels may also be used inaccordance with the present invention.

Referring to FIG. 4, the building panels 10 may be provided with only aolid color ground coat (FIG. 3)

followed by the application of wiped stain on the apparatus 20. Thepanels appear as shown in FIG. 4 and are then covered with a final clearsealer coat. The resulting panels do not have a printed grain pattern asdo the panels of FIG. 6, but instead have only the hand wiped stainappearance with streaks therein as shown in FIG. 4.

Another embodiment of a panel may be provided by eliminating the secondsolid color coating on the flat surfaces (FIG. 5) and following thewiping of the stain with the printing of a grain pattern on the flatsurfaces; This type of panel is similar in appearance to the panel ofFIG. 6 but may have a slightly different subtle undertone more closelyrelated to the color of the first solid color coating.

Although the present invention has been described with reference toseveral illustrative embodiments thereof, it should be understood thatnumerous other modifications and embodiments can be devised by thoseskilled in the art that will fall within the spirit and scope of theprinciples of this invention.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

1. A method of decorating the surface of a building panel comprising thesteps of flowing liquid stain onto said surface, spreading said stainover said surface, and wiping said stain by the application of wovenfabric biased against said surface by a rotating brush, said brushincluding bristles having free outer ends moving relatively against theback side of said fabric to bias the same into wiping contact with saidstain, said bristles positioned for random penetration of the openingsin said woven fabric during rotation.

2. The method of claim 1 wherein said bristles are formed of plasticmaterial and said free ends are bent back, said bristles randomlypenetrating openings in said woven fabric.

3. The method of claim 1 including the step of brushing said liquidstain with a rotary brush to work said stain into said panel surface andremove excess liquid therefrom.

4. The method of claim 3 including the step of partially drying saidstain before wiping thereof by said woven fabric.

5. The method of claim 4 including the step of additionally brushingsaid liquid stain by the application of a high speed rotary brushingafter said first brushing and before wiping thereof by said wovenfabric.

6. A method of decorating the outer surface of a sheet of buildingmaterial comprising the steps of applying liquid stain onto saidsurface; brushing said applied stain at-relatively high speed with aplurality of flexible bristles; and wiping said brushed stain atrelatively low speed with woven stranded material having openingstherein and biased against said surface by a rotating brush havingbristles with free ends movingly penetrating at least some of saidopenings momentarily to form elongated streaks in said stain.

7. The method of claim 6 including the step of working said stain intosaid surface with squeegee means before said high speed brushing.

1. A METHOD OF DECORATING THE SURFACE OF A BUILDING PANEL COMPRISING THE STEPS OF FOLLOWING LIQUIDS STAIN ONTO SAID SURFACE SPREADING SAID STAIN OVER SAID SURFACE, AND WIPING SAID STAIN BY THE APPLICATION OF WOVEN FABRIC BIASED AGAINST SAID SURFACE BY A ROTATING BRUSH, SAID BRUSH INCLUDING BRISTLES HAVING FREE OUTER ENDS MOVING RELATIVELY AGAINST THE BACK SIDE OF SAID FABRIC TO BIAS THE SAME INTO WIPING CONTACT WITH SAID STAIN, SAID BRISTLES POSITIONED FOR RANDOM PENETRATION OF THE OPENINGS IN SAID WOVEN FABRIC DURING ROTATION.
 2. The method of claim 1 wherein said bristles are formed of plastic material and said free ends are bent back, said bristles randomly penetrating openings in said woven fabric.
 3. The method of claim 1 including the step of brushing said liquid stain with a rotary brush to work said stain into said panel surface and remove excess liquid therefrom.
 4. The method of claim 3 including the step of partially drying said stain before wiping thereof by said woven fabric.
 5. The method of claim 4 including the step of additionally brushing said liquid stain by the application of a high spEed rotary brushing after said first brushing and before wiping thereof by said woven fabric.
 6. A method of decorating the outer surface of a sheet of building material comprising the steps of applying liquid stain onto said surface; brushing said applied stain at relatively high speed with a plurality of flexible bristles; and wiping said brushed stain at relatively low speed with woven stranded material having openings therein and biased against said surface by a rotating brush having bristles with free ends movingly penetrating at least some of said openings momentarily to form elongated streaks in said stain.
 7. The method of claim 6 including the step of working said stain into said surface with squeegee means before said high speed brushing. 